Polyether polyurethane has excellent antibacterial property and excellent flexural strength at low temperatures, and particularly excellent hydrolysis resistance, as compared to polyester polyurethane. However, the polyether polyurethane has poor mechanical properties such as abrasion resistance and flexural strength at ambient temperature, and there are some defects in that peeling of a skin layer and molding shrinkage are likely to take place during foaming.
In order to improve the mechanical properties of the polyether polyurethane, there has been proposed to substitute a part or whole of the polyoxypropylene polyol used as a polyol component for polyoxytetramethylene glycol. A usual polyurethane can be practically used as soles having a high density ranging from 0.5 to 1.3 g/cm.sup.3, but it would be difficult to use the polyurethane as soles having a low density ranging from 0.15 to 0.5 g/cm.sup.3, even if the polyoxytetramethylene glycol is used.
An object of the present invention is to provide a polyurethane foam for shoe soles having excellent appearance without any peeling of a skin layer or molding shrinkage in the average density of 0.15 to 0.5 g/cm.sup.3, which is made of a polyether polyurethane having excellent hydrolysis resistance.
The above and other objects of the present invention will be apparent from the following description.